1. Field of the Invention
The invention generally relates to a system for slicing silicon wafers from a boule, and more particularly to an improved system wherein a plurality of band saw blades are simultaneously driven at substantially uniform speeds for simultaneously slicing a plurality of wafers from a commonly related plurality of boules.
2. Description of the Prior Art
It is common practice, of course, to form a boule of silicon by drawing from a liquid melt a rapidly cooling quantity of silicon. The resulting boule is then sliced, employing any one of various techniques and further processed for providing silicon wafers to be employed in the semiconductor industry.
As is well known by those familiar with the fabrication of silicon wafers, the prior art includes numerous techniques for cutting or slicing the silicon wafers from boules of silicon. One technique includes a use of an inside diameter saw adapted to rapidly slice the boule but having a capability of forming a single saw kerf, or slice, in a given cutting operation. Another technique requires the use of ganged blades adapted to be reciprocated for forming multiple saw kerfs whereby multiple slices are formed simultaneously. Unfortunately, a use of reciprocating blades tends to result in a very slow process, the use of such blades is further impaired by frequent and costly breakdowns. Finally, the techniques heretofore employed generally are adaptable for slicing only a single boule of silicon in a given operation.
In view of the foregoing, it should readily be apparent that there currently exists a need for a reliable high-speed system having a capability of slicing multiple wafers simultaneously from a plurality of boules, whereby costs of resulting wafers are reduced for thus enhancing terrestrial uses of silicon solar cells.
It is therefore the general purpose of the instant invention to provide an improved system for slicing a plurality of silicon boules simultaneously to provide a multiplicity of smooth slices particularly suited for use in the fabrication of low-cost solar cells.